HIV-1 (human immunodeficiency virus-1) infection remains a major medical problem, with an estimated 33.6 million people infected worldwide. The number of cases of HIV and AIDS (acquired immunodeficiency syndrome) has risen rapidly. In 1999, 5.6 million new infections were reported, and 2.6 million people died from AIDS. Currently available drugs for the treatment of HIV include six nucleoside reverse transcriptase (RT) inhibitors (zidovudine, didanosine, stavudine, lamivudine, zalcitabine and abacavir), three non-nucleoside reverse transcriptase inhibitors (nevirapine, delavirdine and efavirenz), and five peptidomimetic protease inhibitors (saquinavir, indinavir, ritonavir, nelfmavir and amprenavir). Each of these drugs can only transiently restrain viral replication if used alone. However, when used in combination, these drugs have a profound effect on viremia and disease progression. In fact, significant reductions in death rates among AIDS patients have been recently documented as a consequence of the widespread application of combination therapy. However, despite these impressive results, 30 to 50% of patients ultimately fail combination drug therapies. Insufficient drug potency, non-compliance, restricted tissue penetration and drug-specific limitations within certain cell types (e.g. most nucleoside analogs cannot be phosphorylated in resting cells) may account for the incomplete suppression of sensitive viruses. Furthermore, the high replication rate and rapid turnover of HIV-1 combined with the frequent incorporation of mutations, leads to the appearance of drug-resistant variants and treatment failures when sub-optimal drug concentrations are present (Larder and Kemp; Gulick; Kuritzkes; Morris-Jones et al; Schinazi et al; Vaccaand Condra; Flexner; Berkhout and Ren et al; (Ref 6-14)). Therefore, novel anti-HIV agents exhibiting distinct resistance patterns, and favorable pharmacokinetic as well as safety profiles are needed to provide more treatment options.
Currently marketed HIV-1 drugs are dominated by either nucleoside reverse transcriptase inhibitors or peptidomimetic protease inhibitors. Non-nucleoside reverse transcriptase inhibitors (NNRTIs) have recently gained an increasingly important role in thetherapy of HIV infections (Pedersen & Pedersen, Ref. 15). At least 30 different classes of NNRTI have been described in the literature (De Clercq, Ref. 16) and several NNRTIs have been evaluated in clinical trials. Dipyridodiazepinone (nevirapine), benzoxazinone (efavirenz) and bis(heteroaryl)piperazine derivatives (delavirdine) have been approved for clinical use. However, the major drawback to the development and application of NNRTIs is the propensity for rapid emergence of drug resistant strains, both in tissue cell culture and in treated individuals, particularly those subject to monotherapy. As a consequence, there is considerable interest in the identification of NNRTIs less prone to the development of resistance (Pedersen &Pedersen, Ref. 15).
Certain azaindole derivatives have demonstrated inhibitory activity against HIV. Such compounds, include the compound of formula 8:
which is disclosed in U.S. Pat. No. 6,476,034, herein incorporated by reference in its entirety.
In order to promote the development and production of effective new drugs and treatments for HIV, such as the compounds of U.S. Pat. No. 6,476,034, new methods of preparing these drugs which are more cost and time efficient are required. The present invention seeks to provide such methods.